>> you know, i was just wondering, since you've brought this issue up, we haven't really been able to do much in the united states, the european union has done something in terms of the kind of things you want to see, cap and trade or perhaps a carbon tax or things like that. china and india continue to add a power plant, essentially, every week. so, do you look at that and say climate change is going to happen, no matter what at this point? >> well, some climate change is already happening and will continue to happen. the physics of the problem are quite challenging. we put, well, 85% of the internal used by earth inc., it comes from fossil fuels. and the combustion of those fuels results in us putting 90 million tons of heat-trapping pollution into the atmosphere every day, as if it's an open sewer. it does obey the laws of physics.